In "Heart of Darkness", what has the river come to symbolize?
The journey upstream the Belgian Congo starts off as an adventure story well enough but soon becomes one man's search for truth and his ultimate disillusionment of imperialism and its "values":
Hypocrisy is a salient theme in Heart of Darkness. Marlow's account repeatedly highlights the utter lack of congruence between the Company's rhetoric about "enlightening" the natives with its actual aims of extracting ivory, minerals and other valued commodities. As one of the fevered pilgrims whom he meets on his overland trek tells Marlow, it is not a virtuous idea or even efficiency per se that moves the colonists to treat the natives as members of an inferior species: it is, instead "to make money, of course...'" (p.34).
Even the title of the novel is significant: the "heart of darkness" is neither "the Dark Continent" nor the ignorance and savagery of a primitive people, but rather the greed and perfidity found within the soul when abandoned to its own.
In his essay "Colonialism and Human Nature" (See the enotes reference below), R. Moore qualifies the story as "a searing indictment of European Colonial exploitation, and a symbolic journey into the deepest recesses of human nature."